add subscribing and unsubscribing to threads

util.lua

@@ -105,13 +105,16 @@ function util.split_sentences(sentences, max_sentences)
 end
 
 ---@return string
-function util.get_post_url(req, post_id)
+function util.get_post_url(req, post_id, hash)
+  hash = hash ~= false
   local post = Posts:find({id = post_id})
   if not post then return "" end
   local thread = Threads:find({id = post.thread_id})
   if not thread then return "" end
   
-  return req:url_for("thread", {slug = thread.slug}, {after = post_id}) .. "#post-" .. post_id
+  local url = req:url_for("thread", {slug = thread.slug}, {after = post_id})
+  if not hash then return url end
+  return url .. "#post-" .. post_id
 end
 
 function util.infobox_message(msg)